Abstract: ¹H-NMR and ¹³C NMR of six pairs of α-halocinnamoyt piperidines with substituted aromatic ring are reported. By comparing the ¹H-NMR chemical shift and peak shape of α-H on piperidine ring at various temperatures, the effect of configuration and conformation arc discussed. The configurations of α-halocinnamoyl piperidines were assigned based on chemical shifts and peak shape of a-H on piperidine ring. The correctness of this deduction is also con-firmed by the coupling constants ³J_CCCH of the carbon of carbonyl group and β-proton on the olefinic bond on the ¹³C-NMR.

Key words: α-halocinnamoyl piperidinc NMR, Configuration, Conformation, Chemical shift, Coupling constant